The invention relates to a reactor for evaluating catalysts, and particularly to a plurality of reactors for combinatorial chemistry.
Developments in combinatorial chemistry have largely concentrated on the synthesis of chemical compounds. For example, U.S.Pat. Nos. 5612002 and 5766556 disclose a method and apparatus for multiple simultaneous synthesis of compounds.
WO 97/30784-A1 discloses a microreactor for the synthesis of chemical compounds. Akporiaye, D. E.; Dahl, I. M.; Karlsson, A.; Wendelbo, R. Angew Chem. Int. Ed. 1998, 37, 609-611 disclose a combinatorial approach to the hydrothermal synthesis of zeolites, see also WO 98/36826-A1. Other examples include U.S. Pat. Nos. 5609826, 5792431, 5746982, and 5785927, and WO 96/11878-A1.
More recently, combinatorial approaches have been applied to catalyst testing to try to expedite the testing process. For example, WO 97/32208-A1 teaches placing different catalysts in a multicell holder. The reaction occurring in each cell of the holder is measured to determine the activity of the catalysts by observing the heat liberated or absorbed by the respective formulation during the course of the reaction and/or analyzing the products or reactants. Thermal imaging had been used as part of other combinatorial approaches to catalyst testing, see Holzwarth, A.; Schmodt, H.; Maier, W. F. Angew. Chem. Int. Ed., 1998, 37, 2644-2647, and Bein, T. Angew. Chem. Int. Ed., 1999, 38, 323-326. Thermal imaging may be a tool to learn some semi-quantitative information regarding the activity of the catalyst, but it provides no indication as to the selectivity of the catalyst.
Some attempts to acquire information as to the reaction products in rapid-throughput catalyst testing are described in Senkam, S. M. Nature, Jul. 1998, 384(23), analyze a gas flow from each of the fixed catalyst sites. Similarly, Cong, P.; Doolen, R. D.; Fan, Q.; Giaquinta, D. M.; Guan, S.; McFarland, E. W.; Poojary, D. M.; Self, K.; Turner, H. W.; Weinberg, W. H. Angew Chem. Int. Ed. 1999, 38, 484-488 teaches using a probe with concentric tubing for gas delivery/removal and sampling. Only the fixed bed of catalyst being tested is exposed to the reactant stream, with the excess reactants being removed via vacuum. The single fixed bed of catalyst being tested is heated and the gas mixture directly above the catalyst is sampled and sent to a mass spectrometer.
Combinatorial chemistry has been applied to evaluate the activity of catalysts. Some applications have focused on determining the relative activity of catalysts in a library; see Klien, J.; Lehmann, C. W.; Schmidt, H.; Maier, W. F. Angew Chem. Int. Ed. 1998, 37, 3369-3372; Taylor, S. J.; Morken, J. P. Science, Apr. 1998, 280(10), 267-270; and WO 99/34206-A1. Some applications have broadened the information sought to include the selectivity of catalysts. WO 99/19724-A1 discloses screening for activities and selectivities of catalyst libraries having addressable test sites by contacting potential catalysts at the test sites with reactant streams forming product plumes. The product plumes are screened by passing a radiation beam of an energy level to promote photoions and photoelectrons which are detected by microelectrode collection. WO 98/07026-A1 discloses miniaturized reactors where the reaction mixture is analyzed during the reaction time using spectroscopic analysis. Some commercial processes have operated using multiple parallel reactors where the products of all the reactors are combined into a single product stream; see U.S. Pat. Nos. 5304354 and 5489726.
Applicants have developed a reactor particularly suited for use in combinatorial evaluation of catalysts. Multiple reactors may be readily assembled in an array for the simultaneous evaluation of a number of catalysts. The wells of the multiple reactors may be integrated into a single block, and the reactor inserts of the multiple reactors may be integrated into a single top plate thereby allowing for easy handling and assembly of an array of multiple reactors.
The invention is a reactor for conducting catalytic chemical reactions. The reactor has a well having an open end and a closed end and a first seal retained by the open end of the well. The reactor also has a sleeve having an open end and a bottom end. The bottom end of the sleeve is inserted within the open end of the well. A fluid permeable structure is attached to the sleeve spanning the cross-section of the sleeve and thereby defining a chamber between the closed end of the well and the fluid permeable structure attached to the sleeve. The reactor also has a reactor insert having a fluid permeable end and a top end containing a first and a second fluid conduit. The fluid permeable end of the reactor is inserted within the open end of the sleeve. The top end of the reactor insert is engaged with the first seal. The first fluid conduit is in fluid communication with the chamber; and the second fluid conduit is in fluid communication with the fluid permeable end of the reactor insert. A second seal retained by the reactor insert is engaged with the sleeve.
A preferred embodiment of the invention is one where the apparatus is a plurality of individual reactors, each reactor as described above. Another preferred embodiment of the invention is one where a plurality of wells are attached to a single support, and the corresponding plurality of reactor inserts are attached to a single top plate.